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I have been working with ASP .NET MVC and I use the Moq mocking library to help test the code I write.   Often in ASP MVC anonymous objects are passed around as function arguments.  This is especially common in calls to RouteUrl.  Since I want to be able to test this and verify that it is called correctly I wrote a handy extension method to make it easier called AsMatch.

To be able to test the UrlHelper (since it doesn't have an interface or virtual methods) I wrote a simple wrapper around it with an interface to enable testing.  Using that with this extension method makes testing route generation a breeze.

Given a call to generate a Url like this:

var url = Url.RouteUrl("Show", new { projectName="matt" });

You can write a setup on your Mock of the Url helper using a similar syntax:

UrlHelperMock
.Setup(x => x.RouteUrl("Show",new{ projectName="matt"}.AsMatch()))
.Return("someUrlToTest");

Here is the code that defines the AsMatch extension method:

    public static class ObjectMoqExtensions
    {
        public static object AsMatch(this object @object)
        {
            return Match<object>.Create(testObject => DoObjectsMatch(@object, testObject));
        }
        private static bool DoObjectsMatch(object object1, object object2)
        {
            var props1 = ToDictionary(object1);
            var props2 = ToDictionary(object2);
            var query = from prop1 in props1
                        join prop2 in props2 on prop1.Key equals prop2.Key
                        select prop1.Value.Equals(prop2.Value);
            return query.Count(x => x) == Math.Max(props1.Count(), props2.Count());
        }
        public static Dictionary<string, object> ToDictionary(object @object)
        {
            var dictionary = new Dictionary<string, object>();
            var properties = TypeDescriptor.GetProperties(@object);
            foreach (PropertyDescriptor property in properties)
                dictionary.Add(property.Name, property.GetValue(@object));
            return dictionary;
        }
    }

Have you ever had the desire to convert some RTF text into HTML? Probably not. But if you do, then you are in luck! I recently had the need to do this conversion and after some searching found out a way to do it by enhancing a sample distributed in the MSDN library.  The sample is called: XAML to HTML Conversion Demo. 

The sample has code which converts HTML to and from a XAML Flow Document.  But this doesn’t make things easier until you realize that there is a way to convert RTF to XAML easily. The key is to use System.Windows.Controls.RichTextBox which can load RTF from a stream and save it as XAML.  This conversion is shown below:

        private static string ConvertRtfToXaml(string rtfText)
        {
            var richTextBox = new RichTextBox();
            if (string.IsNullOrEmpty(rtfText)) return "";
            var textRange = new TextRange(richTextBox.Document.ContentStart, richTextBox.Document.ContentEnd);
            using (var rtfMemoryStream = new MemoryStream())
            {
                using (var rtfStreamWriter = new StreamWriter(rtfMemoryStream))
                {
                    rtfStreamWriter.Write(rtfText);
                    rtfStreamWriter.Flush();
                    rtfMemoryStream.Seek(0, SeekOrigin.Begin);
                    textRange.Load(rtfMemoryStream, DataFormats.Rtf);
                }
            }
            using (var rtfMemoryStream = new MemoryStream())
            {
                textRange = new TextRange(richTextBox.Document.ContentStart, richTextBox.Document.ContentEnd);
                textRange.Save(rtfMemoryStream, DataFormats.Xaml);
                rtfMemoryStream.Seek(0, SeekOrigin.Begin);
                using (var rtfStreamReader = new StreamReader(rtfMemoryStream))
                {
                    return rtfStreamReader.ReadToEnd();
                }
            }
        }

With this code we have all we need to convert RTF to HTML. I modified the sample to add this RTF To XAML conversation and then I run that XAML through HTML converter which results in the HTML text. I added an interface to these conversion utilities and converted the sample into a library so that I would be able to use it from other projects.  Here is the interface:

 public interface IMarkupConverter
    {
        string ConvertXamlToHtml(string xamlText);
        string ConvertHtmlToXaml(string htmlText);
        string ConvertRtfToHtml(string rtfText);
    }
    public class MarkupConverter : IMarkupConverter
    {
        public string ConvertXamlToHtml(string xamlText)
        {
            return HtmlFromXamlConverter.ConvertXamlToHtml(xamlText, false);
        }
        public string ConvertHtmlToXaml(string htmlText)
        {
            return HtmlToXamlConverter.ConvertHtmlToXaml(htmlText, true);
        }
        public string ConvertRtfToHtml(string rtfText)
        {
            return RtfToHtmlConverter.ConvertRtfToHtml(rtfText);
        }
    }

With this I am now able to convert from RTF to HTML.  However, there is one catch - the conversion uses the RichTextBox WPF control which requires a single threaded apartment (STA).  Therefore in order to run your code that calls the ConvertRtfToHtml function, it must also be running in a STA.  If you can’t have your program run in a STA then you must create a new STA thread to run the conversion. Like this:

MarkupConverter markupConverter = new MarkupConverter();
private string ConvertRtfToHtml(string rtfText)
{
   var thread = new Thread(ConvertRtfInSTAThread);
   var threadData = new ConvertRtfThreadData { RtfText = rtfText };
   thread.SetApartmentState(ApartmentState.STA);
   thread.Start(threadData);
   thread.Join();
   return threadData.HtmlText;
}
private void ConvertRtfInSTAThread(object rtf)
{
   var threadData = rtf as ConvertRtfThreadData;
   threadData.HtmlText = markupConverter.ConvertRtfToHtml(threadData.RtfText);
}
        
private class ConvertRtfThreadData
{
   public string RtfText { get; set; }
   public string HtmlText { get; set; }
}

Here is the zip contain the code for the Markup converter: MarkupConverter.zip

I don’t know why I didn’t do this long ago, but I am done writing this:

var val = (SomeEnum)Enum.Parse(typeof(SomeEnum),”someString”);

I have typed this too many times and it annoys me. 

I wrote a small extension method on the string type to make this better:

public static class StringExtensions
{
    public static T ToEnum<T>(this string @string)
    {
        return (T)Enum.Parse(typeof (T), @string);
    }
}

With this I can now write the previous line as:

var val = "someString".ToEnum<SomeEnum>()

The xUnit .Net codeplex page lists one useful Visual Studio code snippet for creating a Fact.  As you can tell I am fairly fond of code snippets so I created a few more which I use when writing xUnit.net facts. These are one line snippets that I find very convenient when writing my assertions.

Below is a table which shows the shortcut you use to access the snippet and the code the snippet generates

I have included a zip containing these snippets.   Enjoy!

I was using attributes from the System.ComponentModel.DataAnnotations   namespace for model validation.  This namespace includes a few very useful validation attributes such as

1. Required Attribute – Validates the field has a value
2. Range Attribute – Validates the field is within a given range
3. RegularExpression Attribute – Validates the field matches a given regular expression.

The regular expression attribute is very useful since you can describe exactly what format you want a string property to be in.  While using this though I ran into a problem.  The attribute doesn’t let you specify RegexOptions.  This was an issue for me since I wanted to use the regex to validate that the users input was between 5 and 200 characters long , so I had attribute that property as such:

   1: [RegularExpression(@".{5,200}")]

   2: public string Text{get;set;}

However this doesn’t work since by default the wildcard . does not match new lines (which I am allowing in the input).  The way to fix this is to specify the RegexOptions.SingleLine option to either the Regex constructor or Match function.  The problem is I have no way of doing that here, and there is no argument on the attribute constructor to specify those options.  I was considering overriding the attribute to create one that allows specifying the attribute but then I stumbled upon this:

Regular Expression Options

You are able to specify the regex option inside of the regular expression text! (which I thought was a huge discovery until my co-worker said he knew this all along but never let me know!). 

So I just changed the expression to look like this:

   1: [RegularExpression(@"(?s).{5,200}")]

   2: public string Text{get; set;}

The (?s) is the inline regex option definition so say I want this in SingleLine mode! And now the validation works the way I wanted!